Flexible coupling for pipework

Abstract

A flexible coupling for pipework comprises a rigid sleeve of circular section engaged coaxially around the ends of pipes to be coupled together and connected to each of said ends in sealed manner by means of respective annular gaskets of flexible and resilient material received coaxially in each of the annular gaps between the ends of the pipe and the ends of the sleeve. The sleeve is made up of an assembly of three rigid tubes in alignment along the same longitudinal axis and assembled together in sealed manner by connection means comprising annular gaskets analogous to the above-mentioned annular gaskets and by two sets of laminated blocks which hold the tubes rigidly in alignment on the longitudinal axis, but which allow limited amplitude mutual displacements thereof with resilient return along the axis and around the axis.

We claim: 
     
       1. A flexible coupling for pipework, the coupling comprising a sleeve assembly for circular section coaxially engaged around the ends of the pipes to be coupled together, and being connected to each of them in sealed manner by means of respective annular gasket of flexible and resilient material that are received coaxially in corresponding annular gaps between said ends and respective ends of the sleeve assembly, said sleeve assembly being constituted by at least one assembly of rigid tubes in alignment on the same longitudinal axis and assembled together in sealed manner by connection means which hold them in alignment along said axis, but which allow them limited amplitude mutual displacement along said axis, said at least one assembly of rigid tubes comprising two end tubes spaced apart along the axis and an intermediate tube of different diameter that bridges a gap between the two end tubes, with the connection means between the tubes comprising, between two consecutive tubes, an annular gasket of flexible and resilient material; wherein said connection means are designed to provide resiliency along the above-mentioned axis and further include a set of laminated blocks regularly distributed around said axis, each of the blocks being made up of alternating superposed layers that are rigid and layers that are flexible and resilient, the layers being in the form of cylindrical surfaces centered on said axis, said annular gasket and said set of laminated blocks being inserted side by side in the gap between the two tubes that they connect together, and being fixed to respective facing surfaces belonging to said tubes. 
     
     
       2. A coupling according to claim 1, wherein the intermediate tube is smaller in radius than the end tubes, and is partially engaged inside them. 
     
     
       3. A coupling according to claim 2, wherein the intermediate tube is identical in section to pipes of the coupling. 
     
     
       4. A coupling according to claim 1, wherein the annular gaskets connecting said tubes together are disposed at the ends of the intermediate tube. 
     
     
       5. A coupling according to claim 1, wherein the annular gaskets are fixed around their entire outer periphery and their entire inner periphery to the surfaces of the tubes between which they are interposed. 
     
     
       6. A coupling according to claim 5, wherein the annular gaskets are made of rubber or of elastomer and are fixed to said surfaces by rubber bonding. 
     
     
       7. A coupling according to claim 1, wherein the number of laminated blocks in each of said sets is three or four. 
     
     
       8. A coupling according to claim 1, wherein the sleeve comprises a plurality of assemblies of three tubes disposed in series along a common axis, two consecutive assemblies being connected together by securing end tubes thereof together.